gene therapy

Researchers at the John Radcliffe Hospital used a gene therapy developed by UK biotech company Gyroscope Therapeutics to treat an 80-year old woman with dry AMD in both eyes.

The procedure took place as part of the FOCUS clinical trial which is assessing the safety and biological activity of Gyroscope’s novel gene therapy (GT005) in patients with dry AMD.

The aim of Gyroscope’s therapy is to halt the progress of AMD and preserve patients’ remaining vision. The company hopes it could be used on patients with early AMD to halt the disease before their vision has started to deteriorate.

AMD is the most common cause of sight loss in the UK and affects over 600,000 people. Dry AMD causes a slow deterioration of the macula cells, affecting the central part of a person’s vision and making everyday activities such as reading or recognising faces difficult.

Robert MacLaren, professor of ophthalmology at the University of Oxford carried out the procedure, which could help patients remain independent and improve their quality of life if successful.

"AMD is the number one cause of untreatable blindness in the developed world. A genetic treatment administered early on to preserve the vision in patients who would otherwise lose their sight would be a tremendous breakthrough and certainly something I hope to see in the near future," professor MacLaren said.

The procedure was carried out on Mrs Janet Osborne of Oxford earlier in January, who was motivated to join the trial through the possibility of helping others with AMD.

"I wasn't thinking of me. I was thinking of other people. For me, I hope my sight doesn't get any worse. That would be fantastic. It means I wouldn't be such a nuisance to my family," Osborne said.

The operation involved detaching the retina and injection virus-embedded solution underneath. The virus contains a modified DNA sequence which infects cells and corrects a genetic defect that causes AMD. The effects are thought to be long-lasting meaning that gene therapy would only need to be performed once if successful.

"We're harnessing the power of the virus, a naturally occurring organism, to deliver the DNA into the patient's cells. When the virus opens up inside the retinal cell it releases the DNA of the gene we have cloned, and the cell starts making a protein that we think can modify the disease, correcting the imbalance of the inflammation caused by the complement system.

"The idea of this gene therapy is to 'deactivate' the complement system, but at a very specific point at the back of the eye, so the patient would otherwise be unaffected by it, and we hope that in future it will slow down the progression of macular degeneration," professor MacLaren explained.

Dr Soraya Bekkali, chief executive officer of Gyroscope Therapeutics, said: “Our goal at Gyroscope is to advance new therapies for the treatment of debilitating eye diseases such as age-related macular degeneration. Building on the research of Gyroscope’s scientific founders, we have been working relentlessly over the last two years to advance our first drug development program into the clinic.”

Professor MacLaren added: "This is a rapidly evolving field. Given that we understand a lot more now about the manufacture of the treatment, and the effects of the virus when doing gene therapy at the back of the eye, as well as all the other gene therapy programmes being developed at the moment, I would hope that we'll see a treatment for people with dry AMD within the next few years.”